In a blow molding machine, molds must be replaced according to containers to be blow molded. As a blow mold for blow molding a container from a preform, a pair of blow cavity split molds is necessary. In addition, in order that the bottom portion of a blow molded container can have an inward projecting shape such as a so called champagne bottom shape or a self-standing bottle shape, a raised bottom mold (raised bottom portion) is necessary as a blow mold. Also, in some cases, separately from the pair of blow cavity split molds, a pair of raised bottom molds which are clamped by the blow cavity split molds is necessary.
Patent document 1 discloses a blow mold unit in which a pair of blow cavity and raised bottom mold can be handled as an integral body when replacing molds.